网友您好, 请在下方输入框内输入要搜索的题目:
题目内容
(请给出正确答案)
btn=new Button("ok"); FrameInout() { add(btn); btn.addActionListener(this); } public void ActionPerformed(ActionEvent e){...} } 以上语句中的this是指代btn(按钮)对象。()
此题为判断题(对,错)。
参考答案
更多 “ btn=new Button("ok"); FrameInout() { add(btn); btn.addActionListener(this); } public void ActionPerformed(ActionEvent e){...} } 以上语句中的this是指代btn(按钮)对象。() 此题为判断题(对,错)。 ” 相关考题
考题
下面是一个Applet程序,其功能是进行整数加法运算,要求有3个文本区域,2个作为输入, 1个作为输出,并且由异常处理来判断输入的数字是否为整型,如果是则进行运算,否则抛出异常并显示在第3个文本区域中。请改正程序中的错误(有下画线的语句),使程序能输出正确的结果。注意:不改动程序的结构,不得增行或删行。import java.awt.*;import java.awt.event.*;import java.applet.Applet;/*<applet code="ex17_3.class"width=800 height=400></applet>*/public class ex17_3 extends Applet implements ActionListener{TextField tf1=new TextField(5);TextField tf2=new TextField(5);TextField tf3=new TextField(5);Label l1=new Label("+");Label l2=new Label("=");Button btn=new Button("相加");public void init(){add(l1);add(tf1);add(tf2);add(l2);add(tf3);add(btn);btn.addActionListener(this);}public void actionPerformed(ActionEvent ae) {try{int a=Integer.parseInt(tfi.getText());int b=Integer.parseInt(tf2.getText());int x=a+b;tf2.setText(Integer.toString(x));}catch(NumberFormatException nfe){tf3.setText("error!");}}}ex17_3.html<HTML><HEAD><TITLE>ex17_3</TITLE></HEAD><BODY><applet code="ex17_3.class"width=800 height=400></applet></BODY></HTML>
考题
下列程序使用FlowLayout布局管理器管理3个Button构件在Frame中的位置。请将程序补充完整。注意:不改动程序结构,不得增行或删行。import java.awt.*;public class ex2{private Frame. frm;private Button btn1;private Button btn2;private Button btn3;public static void main(String[] args){ex2 t=new ex2();t.method();}public void method(){frm=new Frame("ex2")______Btn1=new Button("Button1");btn2=new Button("Button2");btn3=new Button("Button3");frm.add(btn1);frm.add(btn2);______frm.pack();frm.setVisible(true);}}
考题
请完成下列Java程序:建立一个Applet程序,包括创建一个画布构件、一个面板构件,面板构件上包含3个按钮,用来设置画布和面板的背景颜色,这3个按钮(Red、Green、Blue)分别控制画布和面板背景色改变为3原色,即红、绿、蓝。要求画布宽度为300,高度为200。注意:请勿改动main()主方法和其他已有语句内容,仅在下划线处填入适当的语句。源程序文件代码清单如下:import java.awt.*;import java.applet.*;/*<applet code="ex10_2.class" width=800 height=400 ></applet>*/public class ex10_2 extends Applet{private Panel pane110_2;private Canvas canvas10_2;private Button btn1, btn2, btn3;public void init(){canvas10_2=new Canvas();canvas10_2. ______;canvas10_2.setBackground(Color.black);add(canvas10_2);pane110_2 = new Panel();pane110_2.setBackground( Color.black );btn1 = new Button( "Red" );btn2 = new Button( "Green" );btn3 = new Button( "Blue" );pane110_2.add( btn1 );pane110_2.add( btn2 );pane110_2.add( btn3 );______;}public boolean action( Event e, Object o ){if( e.target == btn1 ){pane110_2.setBackground( Color.red );canvas10_2.setBackground( Color.red );}else if( e.target == btn2 ){pane110_2.setBackground( Color.green );canvas10_2.setBackground(Color.green);}else if( e.target == btn3 ){canvas10_2.setBackground( Color.blue );pane110_2.setBackground( Color.blue );}return true;}}
考题
下面是一个Applet程序,其功能是接收用户输入的两个整数,比较它们的大小,并在用户按下“比较大小”按钮后,将 Applet中显示的“请先输入两个待比较的整数”,改为“两个整数中最大值是:x”,x是两个数中的最大值。请改正程序中的错误(有下划线的语句),使程序能输出正确的结果。注意:不改动程序的结构,不得增行或删行。程序运行结果如下:import java.applet.*;import java.awt.*;import java.awt.event.*;/*<applet code=LookForMax width=800 height=400></applet>*/public class LookForMax extends Applet implements ActionListener{Label result ;TextField inl,in2;Button btn;int a=0,b=0,max=0;public void init(){result=new Label ("请先输入两个待比较得整数");in1=new TextField(5);in2=new TextField(5);btn=new Button("比较大小");add(in1);add(in2);add(btn);add(result);btn.addActionListener(supper);}public void actionPerformed(ActionEvent e){a=Integer.parseInt(in1);b=Integer.parseInt(in2);if(a>b)max=a;elsemax=b;result, setText ( "两个数中最大值是:"+max);}}LookFormax.html:<html><head><title>A Simple Program</title></head><body><applet code="LookForMax.class" width=800 height=400></applet></body></html>
考题
请完成下列Java程序:用JFrame建立—个窗口,再用网格布局管理器,对窗口布局进行控制,上面有2行2列4个按钮,要求对按钮的大小进行设定,宽度为150,高度为80。注意:请勿改动main主方法和其他已有语句内容,仅在下划线处填入适当的语句。源程序文件代码清单如下import java.awt.*;import java.awt.event.*;import javax.swing.*;public class ex19_2{public static void main(String args[])}JFrame. frm=new JFrame();frm.setTitle("ex19_2");Container cont=frm.getContentPane();______;cont.add(new JButton("button1"));cont.add(new JButton("button2 "));Dimension dimen=______;JButton btn1=new JButton("button3");btn1.setPreferredSize(dimen);cont.add(btn1);cont.add(new JButton("button4"));frm.addWindowListener(new WindowAdapter(){public void winowClosing(WindowEvent we){System.exit(0);}});frm.pack();frm.setVisible(true);}}
考题
下面是一个Applet程序,其功能是根据公式:y=a*sin(x)绘制正弦曲线。要求窗口中有一个文本区作为曲线峰值a的输入,可以判断输入的数字是否符合要求,一个ok按钮,点击则在画布中绘制曲线,以画布中的横坐标值作为sin()的参数x。请改正程序中的错误(有下划线的语句),使程序能输出正确的结果。注意:不改动程序的结构,不得增行或删行。程序运行结果如下:import java.awt.*;import java.awt.event.*;import java.applet.Applet;import java.lang.Math.*;/*<applet code="ex18_3.class" width=800 height=400 ></applet>*/public class ex18_3 extends Applet implements ActionListener {Panel pane=new Panel();drawWnd dw;Label 11 = new Label("峰值");TextField tf1 = new TextField(15);Button btn = new Button("OK");private float a=0;public void init(){pane.setLayout(new FlowLayout(FlowLayout.CENTER,25,5));pane.add(11);pane.add(tf1);pane.add(btn);btn.addActionListener(this);add("North",pane);dw=new drawWnd();add("South",dw);}class drawWnd extends Canvas {drawWnd() {setSize(300,100);setBackground(Color. GRAY);}public void paint(Graphics g) {g.setColor(Color.GREEN);for(int i=0;i<getSize().width-1;i++){int y=0;int y1=y+(int) (Math.sin(i)*a);int y2=y1+(int) (a*Math.sin(i+1));g.drawLine(i,y1,i+1,y2);}}}public void actionPerformed(ActionEvent ae) {try{a=Integer.parseInt(tf1.getText());dw.repaint();}catch(NumberFormatException nfe){tf1.setText("error!");}}}ex18_3.html<HTML><HEAD><TITLE>ex18_3</TITLE></HEAD><BODY><applet code="ex18_3.class" width=800 height=400 ></applet></BODY></HTML>
考题
下面是一个Applet程序,其功能是有两个按钮,分别为First和Second,以及一个Label构件。要求单击 First时能在Label中显示出"Command:First",而单击Second时能显示出"Command:Second",要求只能重载一次 actionPerformed()方法,请改正程序中的错误(有下划线的语句),使程序能输出正确的结果。注意:不改动程序的结构,不得增行或删行。源程序文件代码清单如下:import java.awt.*;import java.awt.event.*;import java.applet.*;/*<applet code=ex04_3.class width=800 height=400></applet>*/Public class ex04_3 extends Applet implements ActionListener{private String str="ok";private Label l;private Button btn;public void init(){setLayout(null);l=new Label(str);l.reshape(10,10,100,30);add(l);btn=new Button("First");btn.reshape(10,50,60,20);l.addActionListene(this);add(btn);btn=new Button("Second");btn.reshape(10,100,60,20);btn.setActionCommand("First");btn.addActionListener(this);add(btn);}public void actionPerformed(ActionEvent ae){str="Command:"+ae.getActionCommand();btn.setText(str);}}ex04_3.html<HTML><HEAD><TITLE>ex04_3</TITLE></HEAD><BODY><applet code="ex2_3.class" width=800 height=400></applet></BODY></HTML>
考题
请完成下列Java程序:记录鼠标在窗口中的信息,包括鼠标的移动事件以及鼠标在窗口中的位置坐标,要求在窗口下方显示鼠标的事件和位置信息,在窗口上方有按钮控制程序的正常退出。注意:请勿改动main()主方法和其他已有语句内容,仅在下划线处填入适当的语句。源程序文件代码清单如下:import java.awt.*;import java.awt.event.*;public class ex12_2extends Frame. implements MouseMotionListener, ActionListenerprivate Label 1;private String str=" ";public static void main(String args[]){new ex12_2();}ex12_2( ){______;setSize(200,200);Button btn=new Button("exit");btn.addActionListener (this);add (btn, "North" );l=new Label(str);add (l, "South" );show ();}public void mouseMoved(MouseEvent event){str="Move: "+l. setText (str);}public void mouseDragged(MouseEvent event){}public void actionPerformed(ActionEvent event){if(event.getActionCommand().equals("exit")){System.exit(0);}}}
考题
下面是一个Applet程序,其功能是打印一个任意进制的乘法表。要求输入乘法表的进制,点击ok则打印出该乘法表。请改正程序中的错误(有下划线的语句),使程序能输出正确的结果。注意:不改动程序的结构,不得增行或删行。程序运行结果如下:import java.awt.*;import java.applet.*;import java.lang.*;public class ex30 3 extends Applet{private TextField tf;private Button btn;public void init(){tf = new TextField(25);add(tf);btn = new Button("OK");add(btn);resize(250, 200);}public void paint(Graphics g){try{int n = tf.getText();int i,j,x=20,y=60;for(i=0;i<n;i++){for (j=1; j<=n; j++) {g.drawString(Integer.toString(i)+"*"+Integer.toString(j)+"="+Integer.toString(i*j),i*x,j*y);}}}catch(NumberFormatException nfe){g.drawString("error number!",20,50);}}public boolean action(Event e, Object o){if (o == "OK"){repaint();return true;}elsereturn false;}}ex30_3.html<HTML><HEAD><TITLE>ex30_3</TITLE></HEAD><BODY><applet code="ex30_3.class" width=800 height=400 ></applet></BODY></HTML>
考题
下列程序使用CardLayout管理了2张卡片,每张都是一个Panel,每个Panel有一个Button,单击按钮,显示下一张卡片中的内容。请将程序补充完整。注意:不改动程序结构,不得增行或删行。import java.awt.*;import java.awt.event.*;public class ex3 implements______{private Panel p1,p2;private Button btn1,btn2;private Frame. frm;private CardLayout cl;public static void main(String[] args){ex3 tt=new ex3();tt.method();}public void method(){Frm=new Frame("CardLayout");Cl=new CardLayout();btn1=new Button("Card1");btn2=new Button("Card2");pl=new Panel();p2=new Panel();p1.add(btn1);btn1.addActionListener(this);p2.add(btn2);______frm.SetLayout(cl);frm.add(pl,"Layer1");frm.add(pl,"Layer1");frm.SetSize{200,200);frm.SetVisible(true);}public void actionPerformed(ActionEvent ae){______}}
考题
请在下列程序的横线处填入正确的语句。 import java.awt.*; import java.awt,event.*; public class ex16 { Frame. f; TextArea ta; Button btn; public static void main(String[] args) { ex16 e = new ex16(); e.m(); } public void m() { f = new Frame("ex16"); ta = new TextArea(); btn = new Button("ok"); btn.addActionListener(new MyAction()); f.add(ta, "Center"); f.add(btn, "South"); f.setSize(100, 100); f.setVisible (true); } class MyAction implements ActionListener { ______ { System. out.println (ta. getText ()); } } }A.static void actionPcrformcd(AcfionEvent e)B.public void action(ActionEwent e)C.public actionPerformed(ActionEvent e)D.public void actionPerformed(ActionEvent e)
考题
阅读以下说明和Java代码,将解答写入对应栏内。【说明】请完成下列Java程序。程序的执行结果是生成一个具有一个TextField类型的对象in、 Button类型的对象btn和Label类型的对象out图形用户界面,程序的功能是计算用户输入数的平方,如图3所示。注意:请勿改动main()主方法和其他已有的语句内容,仅在下划线处填入适当的语句。【程序】import java. awt.*;import java, awt. event.*;public class square {public static void main(String args[ ]){(1)}}class AppFrame. extends Frame{TheAdapterTest listener = new TheAdapterTest( );Text Field in = new TextField (5);Button btn = new Button("计算");Label ut = new Label("用于显示计算结果");public AppFrame( ){setLayout( new FlowLayout( ));add(in);add(btn)add(out);btn. addActionListener( new BtnActionAdapter( ));addWindowListener (listener);setSize(400,100);show( );}class BtnActionAdapter implements (2) {public void actionPerformed((3)) {String s = in. getText( );double d =(4)double sq = d * d;out. setText(d+"的平方是:" +sq);}}class TheAdapterTest extends WindowAdapter{public void windowCIosing((5)){System. exit(1)}}}
考题
下列Applet用于显示提供它的主机的IP地址。请选择正确的语句填入横线处。 import java.awt.*; import java. awt. event.*; import java.applet.Applet; import java.net. *; public class ex23 extends Applet { public void init() { setLayout(new GridLayout(2, 1); Button btm = new Button("显示IP"); final Label 1 = new Label(" "); btn. addActionListener (new ActionListener ( ) { public void actionPerformed(ActionEvent ae) { try { URL ur1 = getCodeBase(); String strName = ur1.getHost(); ______ 1.setText (ia.toString()); } catch (Exception e) { e.printStackTrace (); } } }); add (btn); } }A.InetAddress ia = URL.getByName(strName);B.InetAddress ia = InetAddress.getByName(strName);C.InetAddress ia = new InetAddress.getByName(strName);D.InetAddress ia = InetAddress.getByName(ur1);
考题
本题中,通过菜单“Connect”显示一个对话框,单击“ok”按钮后,所填写的内容就会传回到主窗口并显示出来。import java.awt.*import java.awt.event.*;import javax.swin9.*;public class java3 extends JFrame. implements ActionL-istener{public java3(){setTitle("java3");setSize(300,300);addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});JMenuBar mbar = new JMenuBar();setJMenuBar(bar);JMenu fileMenu=new JMenu("File");mbar.add(fileMenu);connectltem=new JMenuhem("Connect");connecthem.addActionListener(this);fileMenu.add(connecthem);exithem=new JMenuhem("Exit");exithem.addActionListener(this);fileMenu.add(exithem);}public void actionPerformed(ActionEvent evt){Object source=evt.getSource();if(source= =connecthem){Connectlnfo transfer=new ConnectInfo ("your-name","pw");if(dialog= =null)dialog=new ConnectDialog(this);if(dialog.showDialog(transfer)){String uname=transfer.username;String pwd=transfer.password;Container contentPane=getContentPane();contentPane.add(new JLabel("username="+uname+",password="+pwd),"South");validate();}}else if(source= =exitltem)System.exit(0);}public static void main(String[]args){JFrame. f=new java3();f.show();}private ConnectDialog dialog=null;private JMenuhem connecthem;private JMenuhem exithem;}class Connectlnfo{public String username;public String password;public Connectlnfo(String U,String p){username=u;password=P;}}class ConnectDialog extends JDialog implements Ac-tionListener{public ConnectDialog(){super(parent,"Connect",true);Container contentPane=getContentPane();JPanel pl=new JPanel();pl.setLayout(new GridLayout(2,2));pl.add(newJLabel("User name:"));pl.add(username=new JTextField(""));pl.add(new JLabel("Password:"));pl.add(password=new JPasswordField(""));contentPane.add("Center",pl);Panel p2=new Panel();okButton=addButton(p2,"ok");cancelButton=addButton(p2。"Cancel");contentPane.add("South",p2);setSize(240,120);}JButton addButton(Container C,String name){JButton button=new JButton(name);button.addActionListener(this);C.add(button);return button;}public void actionPerformed(ActionEvent evt){object source=evt.getSource();if(source= =okButton){ok=true:setVisible(false);}else if(source= =cancelButton)setVisible(false);}public void showDialog(Connectlnfo transfer){username.setText(transfer.username);password.setText(transfer.password);ok=false;show();if(ok){transfer.username=username.getText();transfer.password=new String(password.get-Password());}return ok;}private JTextField usernameprivate JPasswordField password;private boolean ok;private JButton okButton;private JButton cancelButton;}
考题
本题中,主窗口有一个按钮“打开对话框”和一个文本域,单击按钮“打开对话框”后会弹出一个对话框,对话框上有两个按钮“Yes"和“N0”,单击对话框上的“Yes”和“N0”按 钮后返回主窗口,并在右侧文本域中显示刚才所单击的按钮信息。import java.awt.event.*;import java.awt.*;class MyDialog implements ActionListener{static final int YES=1,N0=0;int message=-1;Button yes,no;MyDialog(Frame. f.String S,boolean b){super(f,S,b);ves=new Button("Yes");yes.addActionListener(this);no=new Button("No"); no.addActionListener(this)osetLayout(new FlowLayout());add(yes);add(no);setBounds(60,60,100,100);addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){message=-1;setVisible(false);)});}public void actionPerformed(ActionEvent e){if(e.getSource()= =yes){message=YES;setVisible(false);}else if(e.getSource()= = no){message=NO;setVisible(false);}}public int getMessage(){return message;}}class Dwindow extends Frame. implements ActionLis-tener{TextArea text;Button button;MyDialog dialog;Dwindow(String s){super(s);text=new TextArea(5,22);button=new Button("打开对话框");button.addActionListener(this);setLayout(new FlowLayout());add(button);add(text);dialog=new MyDialog(this,"Dialog",true);setBounds(60,60,300,300);setVisible(true);validate();addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}public void actionPerformed(ActionEvent e){if(e.getSource()= =button){if(dialog.getMessage()= =MyDialog.YES){text.append("\n你单击了对话框的yes按钮");}else if(dialog.getMessage()= =MyDialog.NO){text.append("\n你单击了对话框的N0按钮");}}}}public class java2{public static void main(String args[]){new Dwindow("java2");}}
考题
●试题六【说明】下面是一个Applet程序,其功能是在绘图区域中通过鼠标的移动来绘制直线,并且有清除绘图区域按钮,用来清除已经绘制的图像。程序运行结果如图5所示。图5import javA.awt.*;import javA.applet.*;/*applet code=ex6_7.class width=800 height=400/applet*/public class ex6_7 extends Applet{private Button btn;private boolean bDraw, bClear;private int upX, upY,downX, downY;public void init(){setLayout(null);bClear = false;bDraw = false;btn = new Button("clear");btn.reshape(250, 150, 70, 30);add(btn);}public void paint(Graphics g){if(bClear){g.clearRect(0, 0, getSize().width, getSize().height);(1) ;}if(bDraw){g.drawLine( (2) );bDraw = false;}}public void update(Graphics g){(3) ;}public boolean mouseDown(Event event, int x, int y){downX = x;downY = y;return true;}public boolean mouseUp(Event event, int x, int y){upX = x;upY = y;(4) ;repaint();return true;}public boolean action(Event event, Object object){if ( (5) ){bClear = true;repaint();}return true;}}ex6_7.htmlHTMLHEADTITLE ex6_7 /TITLE/HEADBODYapplet code=" ex6_7.class" width=800 height=400 /applet/BODY/HTML
考题
●试题六阅读以下说明和Java代码,将解答写入答题纸的对应栏内。【说明】请完成下列Java程序。程序的执行结果是生成一个具有一个TextField类型的对象in、Button类型的对象btn和Label类型的对象out图形用户界面,程序的功能是计算用户输入数的平方,如图3所示。注意:请勿改动main()主方法和其他已有的语句内容,仅在下划线处填入适当的语句。【程序】import javA.awt.*;import javA.awt.event.*;public class square {public static void main(String args[]){(1)}}class AppFrame. extends Frame{TheAdapterTest listener=new TheAdapterTest();TextField in=new TextField (5) ;Button btn=new Button("计算");Label ut=new Label("用于显示计算结果");public AppFrame(){setLayout(new FlowLayout());add(in);add(btn);add(out);btn.addActionListener(new BtnActionAdapter());addWindowListener(listener);setSize(400,100);show();}class BtnActionAdapter implements (2) {public void actionPerformed( (3) ){String s=in.getText();double d= (4)double sq=d*d;out.setText(d+"的平方是:"+sq);}}class TheAdapterTest extends WindowAdapter{public void windowClosing( (5) ){System.exit (1) ;}}}
考题
下面是一个Applet程序,其功能是接收用户输入的两个整数,比较它们的大小,并在用户按下“比较”按钮后,将Applet中的显示的“请先输入两个待比较的整数”,改为“两个整数中最大值:x”,x是两个数中的最大值。请改正程序中的错误(有下划线的语句)并将程序填写完整,使程序能输出正确的结果。注意:不改动程序结构,不得增行或删行。import java.applet.*;import java.awt.*;import java.awt.event.*;public class FindMax extends Applet______{Label result;TextField in1,in2;Button btn;int a=0,b=0,max;public void int(){result=new Label(“请先输入两个待比较的整数”);in1=new TextField(5);in2=new TextField(5);btn=new Button("比较");add(in1);add(in2);add(btn);add(result);btn.addActionListener(this);}Public void actionPerformed(ActionEvent e){a=in1;b=in2;if(a>b)max=a;elsemax=b;btn.setText(“两个数中最大值:”+max);}}Findmax.html:<HTML><HEAD><TITLE>A Simple Program</TITLE></HEAD><BODY><applet code="FindMax.class"width=800 height=400></applet></BODY></HTML>
考题
import java.awt.*; import java.applet.*; public class ButtonDemo extends Applet{ public void init() { Button pushBotton=new Button(“ok”); Button downBotton=new Button(“Yes”); add(pushBotton); add(downBotton); } } 根据以上代码,下列结束正确的是()A、该代码画了一个按钮B、Button(“ok”)创建一个有显示”ok”的按钮C、Button()是构造函数D、按钮属于容器
考题
一个button控件ID为btn_sumbit,双击后得到的处理时间函数名为()A、button_clickB、btn_submit_ClickC、btn_submit_pushD、button_push
考题
inputid="btnGo"type="button"value="单击我"class="btn"/以下哪个选项能够正确地得到这个标签()。A、$("input[type=’button’]")B、$("#btnGo")C、$(".btnGo")D、$(".btn")
考题
inputid="btnGo"type="button"value="单击我"class="btn"/以下哪个选项不能够正确地得到这个标签()。A、$("input[type=’button’]")B、$("#btnGo")C、$(".btnGo")D、$(".btn")
考题
下列关于btn标签的说法正确的是()A、btn-group能将按钮组成按钮组B、btn-toolbar能将btn做成复杂组件C、btn-group可以嵌套使用D、可以使用btn-group-lg,btn-group-sm来调整按钮大小
考题
多选题import java.awt.*; import java.applet.*; public class ButtonDemo extends Applet{ public void init(){ Button pushButton=new Button(“ok”); Button downButton=new Button(“Yess”); add(pushButton); add(downButton); } } 根据以上代码,下列解释正确的是()A该代码画了一个按钮BButton(“ok”)创建了一个有显示“ok”的按钮CButton()是构造函数D按钮属于容器
热门标签
最新试卷